Investigations on the superhyperfine parameters for Cr3+ in the fluorides

The superhyperfine parameters A′ and B′ for Cr3+ ions in K2NaGaF6, K2NaCrF6, KMgF3 and CsCdF3 are theoretically studied from the cluster approach. In the present treatments, the orbital admixture coefficients and the unpaired spin densities in 2s, \( 2{\text{p}}_{\sigma } \) and \( 2{\text{p}}_{\pi } \)2 fluorine orbitals are obtained in a uniform way. The experimental A′ and B′ are reasonably explained, and the unpaired spin densities for the 2s, 2pσ and 2pπ orbitals of the ligand F− are also compared with those in the previous works.